chore(deps): update gcr.io/cloud-sql-connectors/cloud-sql-proxy docker tag to v2.21.0

Signed-off-by: red-hat-konflux <126015336+red-hat-konflux[bot]@users.noreply.github.com>

Author: red-hat-konflux[bot]

charts/maestro-server/values.yaml

@@ -46,7 +46,7 @@ database:
   # Cloud SQL Proxy configuration (for GCP)
   cloudSqlProxy:
     enabled: false
-    image: gcr.io/cloud-sql-connectors/cloud-sql-proxy:2.14.1
+    image: gcr.io/cloud-sql-connectors/cloud-sql-proxy:2.21.0
     # GCP Cloud SQL instance connection name (e.g., "project:region:instance")
     instanceConnectionName: ""